1. Field of the Invention
The present invention generally relates to grinding machines and more particularly to rotating hoppers and feeding assemblies for grinding machines.
2. Background Information
Many different kinds of grinding machines are known in the prior art. Grinding machines include those machines that use a grinding means such as hammer mills, drum chippers, and wheel chippers to grind various materials. Grinding machines are used for grinding tree stumps and slash from logging operations; construction debris from damaged buildings, landfill garbage, tires for compacting purposes, and even apples for apple juice.
Generally and typically, these grinding machines utilize a grinding assembly attached to a frame to grind the material. A hopper or loading container is positioned proximate to the grinding apparatus and introduces material to be ground into the grinding means. In use, the materials are loaded into the hopper, which then holds a quantity of the material to be ground and feeds the material as needed into the grinding means where the material is broken apart or pulverized.
In order to facilitate the passage of materials into the grinding means various forms of hoppers and containers can be used. Some hoppers are stationary. The problem with these hoppers is that as materials sit inside the hopper materials can get stuck and not feed into the grinding means. Also, because the materials are not agitated materials can bridge or arch over the grinding means thus preventing passage of material into the grinding means. As a result, the machines operate less efficiently because material is not fed into the grinding means as rapidly as it can be accepted.
One way of resolving this problem is to utilize a rotating hopper. Material is placed into a hopper, which is rotated by a rotating means. This rotating action, then feeds material into the grinding means by moving the hopper where the material to be ground is located. The movement of the container prevents the stasis of the material in any one location relative to the grinding means, and facilitates the movement of the material to be ground toward the grinding means.
In utilizing a rotating hopper, however, other problems arise. As the drum rotates material may move outward from the drum and into the rotating means. Although these grinding means can grind up hard materials such as stone, wood, metal, and rubber when something as simple as a videotape gets into the rotating means, the means can become fouled and the drum will no longer rotate. When the rotating means no longer works, the material in the drum can no longer be fed into the teeth or hammers and the entire operation must stop. This results in significant losses due to down time and back ups that occur while the rotating means is repaired or replaced. What is needed is a mechanism to prevent material from spilling over the rotating drum into the rotating means. It is an object of this invention to provide a means for preventing material to be ground from entering into the rotating means of a rotating drum on a grinding machine. It is a further object to provide a means for protecting the rotating means of a rotating hopper. It is a further object of the invention to provide a means for efficient filling of a hopper.